I had a strange uunderwater flash issue with my D2X - which I have now solved. And I thought others might find my experience useful.

My Subal D2X housing has two flash wiring options. One with 5 pins connected (iTTL) and one with 3 pins connected (manual with flash ready light).

When I attached my Subtronics with the 3 pins I had a strange problem. The strobes and camera would always fire. But the camera would sometimes not write the image to card. This problem was intermittant. I did quick tests with a Sea and Sea YS90DX and an Inon Z220 and did not have the same problem (although this may have been due to the intermittant nature of the problem).

The way I solved it for the Subtronics was to only connect 2 pins (the Trigger and Ground) and since then the system has been 100% reliable.

Anyway I thought that others might benefit from this.

Alex

p.s. my D2X review following my Red Sea trip will be online soon. I just need help from Eric or James to get it on to the site.

On this note, I have wired up a socket direct to the PC socket on my (EOS1DS) camera. I expect that the D2X shares a feature with the 1DS in that there is a higher degree of circuit protection built into the PC socket (which may have to operate with studio flashes) and so this may be a safer option with older or less known flash units (given that I am unsure what effect tte use of the PC socket will have on rear sync - which is probably unavailable through the PC socket). This said I have no problems running my Seacam (Subtronic) flashes through eith hotshoe or PC connection, but the service engineer that I use has commented that there can be issues surrounding the hotshoe with manual units (I've not tried to obtain an explanation!).

The only two pins which need to be connected are those usually wired to the central hotshoe contact and the outer hotshoe contact - the PC socket may be polarity sensitive! You will need to check in the manual if you want to wire this up.

What wiring is correct for the D2X is continous source of puzzlement to me.

I wanted to be able to use the D2X with a housed SB800 (in iTTL mode) and a manual strobe (as a "fill" flash").

Seacam made me up a "two pin" cable to connect the second strobe. I had expected that the ground and trigger wires be present but Seacam went one step better to provide a functioning ready light. When I test the connectivity then the ground wire is present as is the ready wire. The trigger, SP and quench pins do not connect. Further the cable only works one way round - I have to connect the correct end to the strobe and the other to the housing. If I connect the wrong way round then the stobe is not fired.

I cannot begin to understand this but it works in the following combinations
D2X + SB800 + Seacam 150 (equivalent to Subtronic Alpha)
D1X + SB800 + Seacam 150
D1X + SB800 + Subtronic mini digital
In each case the SB800 is working in iTTL mode and the second strobe is filling in based on the power settings. Just what I want for macro.

but the combination I really wanted
D2X + SB800 + Subtronic mini digital does not work. The flash indicator on the D2X blinks and I cannot take an image.

If anyone could explain the above then I would dearly like to hear from them.
Otherwise the Seacam D2X works perfectly and is a beautiful piece of engineering.

The Ready Light Pin is "THE" source of problems when connecting manual strobes into an ITTL capable camera, this pin must be disconnected. Your manual strobe should have only the X-Sync (trigger) and Ground pins connected. Of course the bulkhead connected to the SB-800 must have all five pins connected.

Now for the difficult part, adding a second strobe when using a Housed SB-800 seems to cause problems with the SB-800's ITTL communication with the camera. You may need to isolate the second strobe by adding a diode into the trigger connection to the second strobe. If there is any feeback from the SB-800 into the second strobe then ITTL will fail.

The simplest solution may be so run the second strobe slaved and set to ignore the pre-flash from the SB-800, if possible. If the second strobe fires during the SB-800's pre-flash burst it will influence and perhaps prevent correct ITTL exposure.

You could try firing the second strobe from the PC socket. I assume that as this is a simple trigger it should/may not interfere with the ittl strobe. If you need a secure PC connector, cut down a Nikon SC-11 cable which screws into the PC socket (this is what I use on the EOS1DS as Canon don't seem to make a cable but do use a threaded PC socket).

OK - try this one on for size. I've been shooting my D2x flawlessly with YS-120s for the past 3 months. Today I replaced my older ailing 120s with a new pair, and I am experiencing the problems you discuss. Same housing, cords etc.

Maybe the new pair has upgraded electronics? Are they close to your older ones in serial number? I had no problem with one Ikelite 200 and one 100a, but I connect them through the Subal 3 pin connection. Does the Seacam has the option for a 3 or 5 pin connection in the housing?

Harald of Seacam told me that it's possible to remove the pins from the hot shoe connector. The pins can be re-inserted simply by pushing them in. I now use this technique to swap from TTL to non-TTL setups.

OK - try this one on for size. I've been shooting my D2x flawlessly with YS-120s for the past 3 months. Today I replaced my older ailing 120s with a new pair, and I am experiencing the problems you discuss. Same housing, cords etc.

Ditto, with D2x in Subal housing. I switched from YS-120s [which worked fine] tp YS90DX, and experienced the same problem. Thought I was going crazy at first. Now I know what to do.

Just thought I'd add my comments. I've been using a Nexus D2X with old YS300 strobes with similar problems - the camera sometimes does not write to the card. However, I can use YS60 with no problems whatsoever - no removal of pins etc etc. Can anyone explain?

I have had some problems with my YS300's in the past and blamed them. Having now just come across this thread I'll do some more experiments, but I still don't understand why the smaller strobes will work - both have ready lights etc etc...

Thanks Luiz - I tried taping that pin over already but with no change. I'll give it a go again see what happens. I spent hours pulling my hair out over this problem on a recent trip to Biak and NOTHING seemed to work!!!!! Hence blaming my strobes themselves...

Today was the first day I've had time to put the D2X into the housing and test controls (OK, more or less) and see if a couple of strobes might work. I immediately ran into the same problems that several people here mentioned - the ready light indicator in the camera viewfinder blinks and the camera will not take a picture.

Based on the discussion here (and the diagram posted by Ike - see URL below)

... I'm assuming that I just need to tape over the readly-light pin on the camera hotshoe plate that would be at 2:00 (looking down and the central connection is in the middle and the other two are at 7:00 and 5:00), as Rocha suggests. That is, I'm assuming that it would be a mistake to try to try to tape over the spring-loaded pin in the hot shoe connector in the housing, and I'm a bit reluctant to try to remove any of the pins in the hot shoe connector. And hope it works.

(I'm sure there's an excellent reason why this camera won't work with strobes and cords as they are out of the box, like it did with the Fuji S2 or previous housed film cameras I've used, and that someday someone will explain it to me.)

Thanks very much for this. This is the sort of important information one might think could be found in Subal's so-called manual for D2N housing, but never mind.

"Cutting the green wire" takes me right back to all those wonderful movies where someone is trying to disarm a bomb as the seconds on a digital clock tick down. Sweat drips from his brow. He moves his wire clippers close to the green wire, then backs away. More sweat from the brow. He moves the clippers closer. ("No, no," someone says, "cut the RED wire, you fool"... BOOM!)

I'll try this tomorrow - having already segued into the single malt stage of the evening.